Re: right whale populations

From: Nancy Stevick (Nancy.Stevick@btinternet.com)
Date: Fri Feb 04 2000 - 07:26:12 EST


On 3 February 2000, Claire wrote:

>Hi Nancy,
>
>I am a fifth grade student doing a research project on right whales. I
>have collected much data on them but have not been able to find any
>information on their populations over the past few decades. Can you help
>me locate any population data on the right whale?
>
>Claire Dockter
>2760 71st St. East
>Inver Grove Heights, MN 55076
>
Dear Claire,

Population trends for the north Atlantic right whale and southern right
whales are very different. Even though both populations were protected from
whaling in the 1930s, the population of southern right whales is increasing
by about 7% each year, while the north Atlantic population is declining from
an already small population of about 350 individuals. If the current trend
of decline continues, north Atlantic right whales will become extinct within
200 years.

Researchers are not certain why this population did not rebound after
whaling was stopped in the 1930s, but they have several theories. They
speculate that it could be because there is not enough food for these
whales. Right whales primarily eat small crustaceans called copepods. The
copepod populations seem to be down, probably due to slight changes in
environmental conditions. If female right whales are not getting enough to
eat, they won't have successful pregnancies.

Many of these whales die as a result of entanglement in fishing gear and by
being struck by ships. North Atlantic right whales spend much of their
lives feeding in major shipping lanes and just don't seem to get out of the
way of ships. Since 1970, there have been 16 known deaths caused by ship
strike and 2 as a result of entanglement in fishing gear. About 62% of
surviving north Atlantic right whales carry scars from gear entanglements
and encounters with ships.

Another problem for north Atlantic right whales could be that there are
simply too few of them. If the gene pool is not large enough, inbreeding
might cause infertility and females might be having miscarriages instead of
successful pregnancies. Researchers are investigating this possibility.

There is a nice article on right whales in the 6 November 1999 issue of New
Scientist. I have a hard copy which has a web address of
http://www.newscientist.com. Perhaps you could obtain a copy of the article
from that if you want additional information.

I hope this helps you with your research.

Best Wishes,
Nancy Stevick



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